Electric switch



Dec. 24, 1929. H. G. BAXTER lET AL v 1,740,533

ELECTRIC SWITCH Filed 'April 18. 1922 30 Z7 3/ ad Z 17g-4 ggz@ l@ ,1e '2 WITNESSES: INVENTOR '1 19 15 Harob/Gaxferd/a Vm Hoo/f7 Mmm @WM ATTORNEY Patented Dec. 24, 1929 UNITED STATES PATENTl OFFICE HAROLD e. BAXTER, OF BALDWIN, AND FRED von HOORN, OF BROOKLYN, NEW YORK,

AsSIGNonS To WEsTINGIIoUsE ELECTRIC a MANUFACTURING COMPANY,4 A Con- PORATIUN QF PENNSYLVANIA ELECTRIC SWITCH .Application tiled April 18,

Our invention relatesto electric switches and particularly to those of the type wherein a thermal cutout or release mechanism is employed.l

l y Our invention has for its Object the .pro-

vision of means whereby a switch may be caused to assume an open position upon the occurrence of a predetermined condition in the circuit controlledv by the Switch.

A further object of our invention is to simplify and improve generally the construction of ush-button Switches.

s shown in the accompanying drawings,

A Figure 1 is a plan view, -of a switch embodying ournvention, a portion of the cover being broken away,

Fig. 2 is a view thereof in side elevation,

the casing beingshown in section,

Fig. 3 is a detail view of the latch-actuating.

mechanism,

Fig. 4 is a `diagrammatic view illustrating the manner in which the switch is connected tothe circuit,'and 1 Fig. 5 is an edge view of the latch-actuating member and its actuating springs.

The switchis mounted in a casing 6 that isfprovided with a cover -7 through which push buttons 8 and 9 project, the push button 8 being normally biased outwardly by a flat spring 10.

A base 12 is mounted within the switch box 6 and serves as a support for a .pair of Stationary contact members-13 4and for a pair of movable contact members `14.

The movable contact members 14 are provided withterminal members 15 and 16 and are'carried by a bracket 18, through acrosshead 19 of insulating material. p

The bracket '18'is pivotally supported upon two posts 21 and itsouter end is normally biased upwardlygby a tension spring 22.

The bracket 18 is engaged, at one end, by a latch .'23 that is normally biased inwardly by a spring 24. The latch v23 is provided with `a cam Surface that is engaged by the lower end of the push button 8 when it isy d sired -to eiect an opening, ofthe switch manually. The push button 9 is employed Y forreturning the contact members 14 to 5.o, closed position, againstv the tension rofthe 1922. Serial No. 555,386.

spring 22.'4 It will be observed that the latch will be snapped into locking engagement with the bracket 18, whenever the contact members 14 gre moved to closed position.

latch-actuating member 27, such fas a notched collar, is supported by a shaft 28 that is carried in a bracket 28a. which is fastened to the base 12. The shaft 28 is in series with the circuit 29 that is controlled by the switch (see Fig. 4) and is of resistance material so that it will become heated during the presence of an abnormal current in the circuit. 4

The member 27 is normally held against turning movement on .the shaft 28 by reason of a fusible material, or solder 30. (Fig. .)v However, upon an abnormal or predetermined increase of'current in the circuit, the resistance member 28 becomes heated and the fusiblematerial 30, is softened, to permit turning movement of the member 27, under the action of one of the springs 31 and 32, each of which has its ends secured to the bracket 18 and the member 27, respectively. In the position shown in- Fig. 2, the spring 31 is under tension and the actuating member 27 is in set position. If, now, the fusible' member 30 be softened, as has been explained, the member 27 will be turned in a clockwise direction, tripping the latch 23 clear of the bracket 18. This operation permits the bracket 18 to-be moved about its ivot, by the spring 22, in a clockwise irection. During this movement, the tension of the .spring 31 Iis lessened and that of the spring 32increased, thus causing the actuating mem- -ber 27 to then move in a counter-clockwise direction to its set position. as shown in Fig.

2. A shouldered portion27a, together with the upstanding portion of the bracket 28a, serves -t'o limit this movement of thefmenr ber 27. It will be understood that, upon tripping the latch 23, the movements just described occur in rapid sequence, s o that the member 27 is returned to set position before the fusible member 30 has had suiiicient time to becoine cool.

From the foregoing, it willbe Aseen that we provide a switch that is readily operable .either automaticallyE or manually and one wlnzrein repeated operations will not affect the operativeness thereof.

Various modifications in detail and general arrangement may be made without departing from the spirit and scope of the invention as defined in the accompanying claims.

We claim as our invention:

l. The combination with a circuit interrupter that is normally biased to one position, of a latch for holding the interrupter in another position, a shaft mounted in xed position, a thermally-controlled element rotatably mounted thereon and adapted to release the latch under predetermined conditions, means actuated by the movement of the interrupter to return the said element to its former position after each actuation thereof and manually operable means for tripping the latch.

2. The combination with a circuit interrupter that is normally biased to one position, of a latch for holding the interrupter 1n another position, a shaft associated with the circuit interrupter, a thermally-controlled element rotatable on the shaft to release the latch under predetermined conditions, and a tension device actuated by the movement of the interruptor to return the said element to its former position during each opening movement of the interrupter.

3. The combination with a movable switch member normally biased towards one position, of a latch for holding it in another position, an actuating member for the latch, a tension member for moving the said member to trip the latch, a y,tension member for returning the actuating member to its starting position, and means whereby the effective force of the said tension members is varied upon movement of the said switch members.

4. The combination with a movable switch member normally biased towards one position, a latch for holding it in another position, an actuating member for the latch, a tension member for moving the said member to trip the latch, a tensionmember for returning the actuating member to its starting position, and means whereby the tension members are alternately caused to move the actuating member as the said switch member is' moved back and forth.

5. The combination with a movable switch member normally biased towards one position, a latch for holdin it in another position, an actuating mem e'r for the latch, a thermal element for holding the actuating member against movement under predetermined conditions, a tension member for moving the said member to trip the latch, a tension member for returning the actuating member to its starting position, and means whereby the effective force of the said tension members is varied upon movement of the said switch member.

6. The combination with a movable switch member normally biased towards one position, a latch for holdinfr it in another position, an actuating memtber for the latch, a. thermal element for holding the actuating member against movement under predetermined conditions, a tension member for moving the said member to trip the latch, a tension member for returning the actuating member to its starting position, and means whereby the tension members are alternately caused to move the actuating member as the said switch member is moved back and forth.

7. The combination with a circuit interrupter that is normally biased to one position, of a latch for holding the interrupter in another position, means for manually tripping' the latch, a shaft mounted 1n fixed position, a thermally-controlled element fixed to the shaft adapted to be freed therefrom to automatically release the latch under predetermined conditions, and means actuated by the movement of the interrupter to return the said element to its former position after each automatic operation thereof.

8. The combination with a movable switch member normally biased toward open position, of a latch for holding it closed, a fusible element, a tensioned member normally held by the fusible element, a resistance member in the circuit controlled by the switch to effect heating of the fusible element, means for tripping the latch upon release of the said tensioned member, and means for returning the said member to set position after the latch has been tripped.

9. The combination with a movable switch member normally biased toward open position, of a latch for holdin the switch member in closed position, a t ermally-actuated andautomatically resettable fusible element for tripping the latch, a resistance for heating the thermal element and means for manually tripping the latch.

10. The combination with a movable switch member normally biased toward open position, of a latch for holding it in closed position, a thermally-actuated element for tripping the latch, means for exerting a tensional force upon the said element, and means for shifting the direction of tensional force at each operation of the switch.

11. The combination with a movable switch member normally biased toward open position, of fa latch for holding the switch member in closed position, a thermally-controlled element for tripping the latch, means actuated by the said movable member for resetting the said element, and means for manually tripping the latch.

12. In a switch, a shaft., a latch member mounted on the shaft, a plurality of springs attached to the latch member to exert different turning moments about the shaft, and

anchoring means for the springs, one of the springs normally being in a stressed condition and another sprin normally being in an inactive condition w ereby, upon the actuation of the latch member by the irst spring, the second spring is partially stressed to return the member to its initial position.

13. In combination, a shaft, a latch member mounted thereon, a plurality of springs attached to said member at different peripheral points, anchoring means for the springs, and latching means for the member, one of the springs normally biasing the member to movement upon the release of the latch, another spring being stressed during the operation of the iirst spring for retrieving the member.

14. The combination .with a movablev switch member normally'biased towards one position, of avlatch for olding it in another position, an actuating member for the latch comprising a collar soldered to a shaft, a tension member formoving the collar to trip the latch upon the softening of the solder, and a second tensioning member for returning the collar to its initial position after the latchvis tripped and before the solder becomes hardened.

In testimony whereof, we have hereunto subscribed our names this 17th day of April,

HAROLD G. BAXTER.

FRED voN HOORN. 

